I intend to take my spare RAM, as well as USB drive enclosure (provided I can find all the parts, as it's disassembled!). My intentions are to remove the drive from your computer and plug it into my parents' laptop and have that computer thoroughly scan the drive for viruses while we wait (and maybe defrag it while I'm at it). Meanwhile I could always have Memtest86 running on your machine. I have a spare monitor to use if you don't want to take your LCD screen.

You should also bring your original Windows XP install disc, along with its activation code. That never hurts. I don't have any hard drives to spare, though.